Thread feeding and tensioning apparatus for knitting machine



Nov. 8, 1966 L. KING 3,283,543

THREAD FEEDING AND TENSIONING APPARATUS FOR KNITTING MACHINE Filed April16, 1964 2 Sheefs-Sheet 1 J L, W TTF I 36 "[W H M'\" w 1 i l ;ii|| I I i/4 l6 Par-M PM kw-l m 00-0 000000000 2 OOOOOOHOI O 0% 2 t 44 42 0 l8 180 1 60 Lawrence King 82 68 INVENTOR BY 40 54 WWO ATTORNEY Nov. 8, 19661.. KING 3,283,543

THREAD FEEDING AND TENSIONING APPARATUS FOR KNITTING MACHINE Filed April16, 1964 2 Sheets-Sheet 2 FIG 5 Lawrence King INVENTOR United StatesPatent 3 233,543 THREAD FEEDING A ND TENSIONIN G APPARA- TUS FORKNITTING MACHINE Lawrence King, New York, N.Y., assignor to Rosfor MillsCorporation, New York, N.Y., a corporation of New York Filed Apr. 16,1964, Ser. No. 360,211 3 Claims. (Cl. 66-432) This invention relates tocircular knitting machines and more particularly it relates to apparatusfor feeding thread to such machines under uniform tension. It hasparticular reference to elastic or stretchable threads which are knittedinto tubular items such as garments.

It is obvious that in order to knit a garment which is commerciallyacceptable, the finished garment must be free from imperfections orirregularities. When the garment is to be knit of elastic thread, theproblem becomes more acute since minor variations in tension will tendto variably elongate or stretch the thread, thus creating a finishedgarment with some of its threads stretched more than others. This notonly tends to create unsightly wrinkles and gathers, but also produces agarment which does not fit properly. Neither of these conditions isacceptable in a quality garment and it hence becomes necessary toprovide a means for applying a uni-form tension to all elastic threadsbeing fed to the knitting machine.

Another, though no less serious, problem occurs when the elastic threadfeeding means is intermittently started and stopped. If the thread feedsfreely off a supply roll, a sudden stopping of the knitting machine maycause a slack to occur in the thread at some point between the supplyroll and the machine knitting needles. If the thread is at all twisted,such a slack may allow the thread to kink or knot. However, even if thethread is not twisted, the slack may vary between different adjacentthreads. Then, when the knitting machine is started again, the slackmust be taken up, but since the slack in each thread might be different,the result might again be a garment having an uneven appearance due tovariable tension on each of the threads which are knitted to form thegarment. Also, if knots or kinks occur when the thread is slack, theymay remain in the thread and become knitted into the finished garment,thus ruining its appearance.

In the conventional form of circular knitting machine, the thread issupplied from a plurality of juxtaposed thread supply rolls and is feddownwardly to a series of circularly arranged knitting needles.Recognizing that a free feed of the thread will not produce a uniformlyknitted garment, various attempts have been made to interpose atensioning means between the thread supply rolls and the knittingneedles, but such past attempts have not been altogether satisfactory.One prior art approach was to feed the thread between an intermeshingpair of gears or toothed rollers which were to provide a tensional forceon the thread. However, the interaction of the mating gear teeth causedthe thread to become mangled or crimped and thus unsuitable for theknitting of smooth garments. Another approach taken in the prior art wasto utilize adjustable tapered rollers, but these tapered rollers weredifficult to set and adjust and failed to provide a positive,non-slipping thread feeding and tensioning means. Other prior artapproaches failed to properly synchronize the tensioning means with theknitting machine itself with the result that intermittent starting andstopping of the machine would not necessarily start or stop thetensioning means, and thus the thread fed to the machine was notuniformly ten-sioned.

It is, therefore, an object of the present invention to overcome thedifficulties and deficiencies associated with the prior art and toprovide an improved thread feeding and tensioning apparatus forsupplying elastic thread to a circular knitting machine.

Another object of the present invention is to provide apparatus forfeeding elastic thread under uniform tension to the needles of acircular knitting machine.

Another object of the present invention is to provide an elastic threadtensioning means which operates in synchronism with a machine forknitting the thread and which thus provides a positive feed for thethread.

Another object of the present invention is to provide thread tensioningapparatus for a circular knitting ma- Other objects, advantages andsalient features of the 7 present invention will become apparent fromthe follow- 'ing detailed description, which, taken in connection withthe annexed drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

FIGURE 1 is a side elevational view of a portion of i a circularknitting machine having a thread feeding and tensioning apparatus, inaccordance within the principles of the present invention, affixedthereto;

FIGURE 2 is a fragmentary bottom view taken substantially along line 22of FIGURE 1;

FIGURE 3 is a fragmentary developed side elevational view takensubstantially along line 3-3 of FIG- URE 2;

FIGURE 4 is a transverse sectional view taken sub- 5 stantially alongline 44 of FIGURE 3;

FIGURE 5 is a fragmentary end elevational view taken substantially alongline 55 of FIGURE 4; and

FIGURE 6 is a fragmentary sectional view taken substantially along line66 of FIGURE 5.

In accordance with the principles of the present inventron and as can beseen from the various figures therei of, there is provided a circularknitting machine generally designated 10, a support means secured to theknitting machine and generally designated 12, a mounting membergenerally designated 14 aifixed to the support means, a tensioning meansgenerally designated 16 secured to the mounting member, a drive meansgenerally designated 18 also secured to the mounting member and operableto drive the tensioning means, and a knitting machine drive mechanismgenerally designated 20 which operates the knitting machine 10.

Referring now to FIGURE 1, the upper portion of a circular knittingmachine 19 is shown as having a cam plate 22 and a needle mounting plate24 juxtaposed beneath the cam plate and rotatable relative thereto. Aplurality of conventional needles, not shown, are pivotally aflixed tothe needle mounting plate 24 and a plurality of feed-in heads 26 areequally spaced about the periphery of the cam plate 22. As the feed-inheads 26 supply thread to the needles, the needles and their mountingplate 24 are rotated relative to the cam plate 22, and

this relative rotation effects a knitting operation to produce a tubularknitted article 28 in a manner which is well known to those skilled inthe art.

A support means 12 extends above the knitting machine 16 to support thethread, the thread guide means, and the tensioning means. The supportmeans 12 is formed by a stationary elongated central shaft 30 having athread support plate or ring 32 suitably attached to the shaft 30,

such as by a plurality of spaced spokes or ribs, not shown. 7

The plate or ring 32 has a flat upper surface 34 from which a pluralityof spaced pins 36 project upwardly. The

Patented Nov. s, was

3 pins 36 serve as a mounting means for supply rolls or coils 38 ofthread 40 which are placed over the pins 36 to rest upon the flatsurface 34. Although only one such coil or supply roll 38 is shown inFIGURE 1, it should be understood that this is only for ease ofillustration and that, in actual operation, a plurality of such rolls 38are used with one being placed over each pin 36 to supply a plurality ofthreads 40 to the knitting machine 10.

While the thread 49 can be of any suitable material to be utilized inknitting the article 28, the presesent invention is particularlydirected toward elastic or stretchable threads such as those formed ofspandex fibers. Such threads are sol-d commercially under the trademarkLycra manufactured by E. I. du Pont de Nemours and Co. of Wilmington,Delaware.

A pair of guide roller mounting members 42 are suitably afiixed to thesupport means 12, with one of such members 42 being located at the upperend of the shaft 30 and the other of such members being located near thelower end of the shaft 30 adjacent the knitting machine It). A pluralityof rotatable guide rollers 44 are spaced from the peripheries of thesemembers 42 by suitable means such as outwardly extending legs 44integral with the members 42. Between the upper member 42 and thesupport ring 32, an eyelet mounting ring 46 is suitably afiixed to theshaft 36 by means of spokes or ribs. A plurality of equally spacedspokes 48 extend away from the periphery of the ring 46 and are providedat their outer ends with eyelets 56 through which the thread 46 passes.

As can be seen from FIGURE 1, a coil or supply roll 38 is placed over apin 36 to rest upon the flat upper surface 34 of the thread support ring32. Thread 40 from the coil 38 feeds upward through an eyelet 50 andover an upper guide roller 44, and then traverses downward inside therings 46 and 32 and finally feeds into the tensioning means 16. Thistensioning means applies a constant and uniform tension to each threadand after a thread 40 exits from the tensioning means, it feeds downwardand over a lower guide roller 44 and into a feed-in head 26 whichsupplies the thread 40 to the needles. It can be seen that for eachsupported supply coil 38, there is an associated eyelet 50, upper andlower guide roller 44, feed-in head 26 and special portion of thetensioning means 16, so that each individual thread 40 is fed from itssupply roll to the needles under exactly the proper conditions of speedand tension. When all of the threads 40 are considered together, themeans for feeding and tensioning them comprises the apparatus which isthe subject matter of the present invention.

Referring now to FIGURES 2 through 6, it will be seen that the mountingmember generally designated 14 is formed as a fixed ring which isattached to the shaft 30 by means of integral upper spokes 52 and lowerspokes 54. As can be seen from FIGURE 4, the ring or mounting member 14is generally tubular in configuration and rectangular in cross-section,and when the ring is mounted in its norm-a1 position on the shaft 30, awall 56 forms the upper Wall, a wall 58 forms the lower wall, a wall 649forms the inner wall which is close to the shaft 30, and a wall 62 formsthe outer wall.

The tensioning means 16 is supported by the mounting member 14 andincludes a plurality of coacting pairs of rollers 64 and 66. Each ofthese rollers is generally cylindrical in shape, is provided with asmooth outer surface andis fabricated of a plastic material, preferablynylon. Each pair of rollers 64 and 66 is spaced from the adjacent pairsso that each pair can be individually and positively driven by the drivemeans 18. One individual thread 40 feeds between each roller 64 and itsassociated roller 66.

Only the roller 64in each pair of rollers is positively driven by thedrive means 18. The roller 66 in each pair is merely freely mounted asan idler and is driven by means of frictional contact from the drivenroller 64. Each roller 64 is provided with a stub shaft 68 which extendsthrough apertures in the side walls 60 and 62 of the mounting member 14,and, adjacent the'inner Wall 60, a

spur gear 70 is mounted on the end of the stub shaft 68. Each roller 66is also provided with a stub shaft 72 which extends through the walls 66and 62 of the mounting member 14, but the apertures through which theseshafts 72 pass are formed as elongated slots 74, as can be seen inFIGURES 3 and 6. Adjacent the inner Wall 69, the ends of the shafts 72are flared outwardly as shown at '76 to thus permit the shafts to slidewithin the slots 74 but to prevent them from retracting through theslots.

The purpose of providing the slots 74 for the shafts 72 which mount therollers 66 is to permit the rollers 66 to be slidable toward and awayfrom their associated rollers 64 to thereby accommodate threads 40 ofvarying diameters. However, means are provided for spring-biasing eachroller 66 toward its associated driven roller 64. This means, as shownin FIGURES 4 through 6, includes a U- shaped bracket having an elongatedleg 78 in parallel juxtaposition to the outer wall 62, another elongatedleg 80 in parallel juxtaposition to the inner wall 60, and a transverseleg 82 interconnecting the legs 7 8 and 80 at one end thereof. At theend of the bracket opposite the wall 82, a slot 84 is formed in the legs78 and 80 for reception of the shaft 68, as shown in FIGURE 5. Alignedapertures are formed through the legs 78 and 86 and these apertures aresized to accommodate the shaft 72. It can thus be seen that the shaft 72and its interconnected roller 66 are mounted within the U-shaped bracketand that the bracket and shaft are slidable toward and away from theroller 64, within the shaft 72 being slidable within the slots 74.

When the driven shaft 68 becomes fully positioned within the bracketslot 84, the slidable motion of the bracket is halted and in thisposition, the rollers 64 and 66 should be in contact and the shaft 72should be at the near end of the slot 74. This condition is shown inFIG- URE 5 and should only occur when no thread 40 is present betweenthe rollers 64 and 66. When a thread 40 is introduced between therollers, the roller 66 must move slightly away from its associatedroller 64 to accommodate the thickness of the thread. This slight movingcauses the shaft 68 to move slightly out of its slot 84 and causes theshaft 72 to move slightly toward the far end of its slot 74. Eachbracket is spring-biased to normally urge the rollers 64 and 66 towardone another and to resist this slight sliding or parting movement of therollers. To this end, a pin 86 extends inward from the bracket leg 78and a similar aligned pin 83 extends inward from the outer mountingmember wall 62. Between these pins 86 and 88, a coil tension spring 90is mounted, and this coil spring pulls the bracket toward the pin 88 andthus biases the rollers 64 and 66 toward one another.

In order to operate the gears 70 and cause their associated pairs ofrollers 64 and 66 to tension the thread 40, a drive means 18 isprovided. The drive means includes a ring gear 92 having an upper seriesof teeth 94 and a lower series of teeth E6. The ring gear 92 is slidablymounted within a groove 98 formed in the lower portion of the inner wall60 on the mounting member 14 as shown in FIGURE 4. Of course, ifdesired, suitable bearing means may be provided between the ring gearand the mounting member, and although bearing means have not beenillustrated in order to simplify the description of the invention, theywill be readily apparent to those skilled in the art. The ring gear 92can also be provided with a series of spaced spokes or ribs 100 whichinterconnect to a hub 102 surrounding the shaft 30, as shown in FIGURE6. In operation, the ring gear and its interconnected hub are rotatedrelative to the mounting member and this ring rotation causes the rollerdriving gears 70 to rotate, since these driving gears 76 mate with theupper series of ring gear teeth 94, as shown in FIGURE 3.

The drive means 18 also includes a drive gear 104 which mates with thelower series of ring gear teeth 96, as shown in FIGURES 2 and 4, andwhich eifectuates the rotation of the ring gear 92. The drive gear issuitably mounted within a bearing 106 aflixed to the lower Wall 58 ofthe mounting member 14, as shown in FIGURES 2 and 4. The drive gear isoperatively connected to a variable speed control unit 108 by flexiblemeans in the form of links 110 having universal joints 112 therein. Theuniversal joints permit the links 110 to be interfolded and bent in sucha manner that the variable speed control unit 108 can be directlyconnected to the knitting machine drive mechanism 20 for operation insynchronism therewith.

It can thus be seen and appreciated that the drive means 18 and thus thetensioning means 16 are interconnected with and operable in synchronismwith the knitting machine drive mechanism 20 and hence with the knittingmachine itself. The variable speed control unit 108 is provided with amanually adjustable means 114, as shown in FIGURE 2, for varying thesetting of the unit. By altering the setting of the adjustable means114, the tension which the roller pairs exert on the thread 40 can bevaried accordingly. This can be best understood by first assuming acondition wherein the unit 108 is adjusted to substantially the samespeed as the knitting machine drive mechanism so that thread 40 is fedto the needles at just the same speed at which the needles knit it. Insuch a condition, there would be no tension at all on the thread exceptthat caused by friction. However, if the unit 108 is adjusted to run therollers at a speed slightly slower than that of the knitting machine,the result is that the roller pairs fail to supply the thread as fast asthe needles are knitting it and consequently, between these roller pairsand the needles, the thread is under tension due to the pull of theneedles. Naturally, the slower the unit 108 is set, the slower will bethe speed of the rollers and hence the greater will be the tension onthe thread.

Since a single drive gear 104 drives the ring gear 92 and causes it torotate, and since this ring gear rotation causes the roller drivinggears 70 to rotate, it can thus be considered that the drive gear 104positively drives the tensioni-ng rollers 64 and 66. Since each pair ofrollers is positively driven from the same source, each thread 40 issubjected to the same amount of tension and consequently all of thethreads are delivered to the needles with exactly the amount ofelongation. A further feature of the present apparatus is that thetensioning means 16 operates responsively to the knitting machine drivemeans 20. Thus, if the knitting machine 10 is stopped for some reason,the feeding of the threads 40 is also simultaneously stopped and whenthe knitting machine is started again, the threads will continue feedingat exactly the same speed and tension as was present prior to theknitting machine stoppage. It will thus be appreciated that the knittingmachine 10 can be started and stopped several times during the processof producing a single knitted article 28, but all of the thread 40 whichis utilized to form the article will be delivered to the needles withexactly the same tension and hence exactly the same degree ofelongation.

In operation, the knitting machine operator determines exactly whatdegree of tension should be applied to the threads 40 and he sets themanually adjustable means 114 accordingly. The knitting machine 10 isthen started and the knitting machine drive means 20 puts the plates 22and 24 into relative rotation. Operation of the drive means 20 producesa responsive but selectively slower operation of the variable speedcontrol unit 108 and when the unit 108 starts to operate, it transmitspower through the links 110 and causes the drive gear 104 to rotate.Since the drive gear 104 is fixed in position and in engagement with thelower series of teeth 96 on the ring gear 92, rotation of the drive gear104 causes the ring gear to move relative to the mounting member 14 andto revolve about the shaft 30. Such ring gear movement causes the manyspur gears 70, which are engagement with the upper series of teeth 94 onthe ring Meanwhile, each of the various threads 40 has been 1 fed upwardoff its coil 38, through an eyelet 50, over an upper guide roller 44 andback down to pass between a pair of rollers 64 and 66. Since the rollersin the pair are biased toward one another by means of the tension spring90, each ro l ler tightly grips against one side of the thread 40 androtation of the driven roller 64 causes a corresponding oppositerotation of the roller 66 to hence feed the thread 40 downward towardthe needles. Since the rollers 64 and 66 are formed with smooth outersurfaces, the threads passing between them will not be mangled orcrimped in any way.

After the threads 40 pass from between the rollers 64 and 66, theyproceed downward over lower guide rollers 44, through feed-in heads 26and into the needles mounted on the plate 24. Since the speed oftheknitting machine 10 is somewhat faster than the speed of the tensioningmeans 16, the needles tend to utilize the thread faster than it is beingsupplied to them from the tensioning rollers 64 and 66, and since theneedles cannot get the thread 40 fast enough, they pull upon that threadavailable to them and thereby elongate it, thus applying a tension tothe threads. The tension is uniform between each pair of tensioningrollers and each associated needle and the result is that all threadsknitted into the article 28 are tensioned or elongated exactly the sameamount.

After reading the foregoing detailed description, it will be apparentthat the objects set forth at the outset of this specification have beensuccessfully achieved. Accordingly,

What is claimed is:

1. In a knitting machine having a plurality of circularly arrangedneedles, a plurality of thread supply rolls providing elastic thread forthe needles and a knitting machine drive mechanism, the improvementwhich comprises apparatus for feeding the elastic thread to the needlesunder a selectively variable, constant and uniform tension,

said apparatus including a mounting member in the form of a fixed ringjuxtaposed above the needles in the knitting machine,

said ring including an inner vertically extending wall and a juxtaposedgenerally parallel, outer wall defining a space therebetween,

a plurality of pairs of thread tensioning rollers carried by saidmounting member with said rollers positioned on the outside of saidouter wall of said rlng,

each of said pairs of thread tensioning rollers including coacting,smooth surfaced, rollers having cylindrical portions between which thethread passes,

each of said rollers including a stub shaft rotatably supported by saidring,

said stub shaft of one of said rollers of each of said pairs extendingthrough said outer and inner walls of said ring and carrying a rollergear on the inside of said ring,

a common tensioning roller drive means operatively associated with allof said roller gears, resilient means carried within said space andoperatively engaging said stub shaft of the other roller of each of saidpairs to urge said other roller toward said nected with tlhe knittingmachine drive mechanism '1? 5 and being operable independently of theknitting ma- References Cited by the Examiner sai c l n dnge bff i videdwith two se arate sets UNITED STATES PATENTS 1 s of 1;; r 1 g .p p1,097,115 5/1914 Wutsch 66-132 a drive gear operatively interconnectedwith said var- 5 2,290,628 7/1942 Alderfer 66 132 iable speed controlmeans and interengeuging with 2318998 5/1943 Ingaus 66 132 one of saidsets of teeth of said ring gear, I 2,542,816 2/1951 Keflt 66-132 theother of said sets of teeth of said ring gear inter- 8 1/1952 Heller 66132 engaging with n of Said roller gears, 2,697,337 12/1954 BI'O'WII et:al. 66-56 operation of the knitting machine causing a synchro- 1O2736178 2/1956 Lawson 66 56 nized and simultaneous driving of saidthread ten- 3,010,299 11/1961 Shannon 66'56 sioning rollers to feedthread to the needles, and ad- 3,158,013 11/1964 Mfmday 66 56 justmentof said variable speed control means eflect- 3325570 12/1965 Mlslhcon 66132 ing a simultaneous and uniform modification of the tension on theelastic thread being fed toall of the 15 FOREIGN PATENTS needles of theknitting machine. 1,045,587 12/1958 Germany- 342,297 1/ 1931 GreatBritain. 456,919 11/ 1936 Great Britain. 745,909 3/ 1956 Great Britain.773,090 4/ 1957 Great Britain.

2. The improvement defined in claim 1 wherein said variable speedcontrol means is operatively interconnected with the knitting machinedrive mechanism for responsive operation synohronously therewith, andflexible means 20 'operatively interconnecting said variable speedcontrol MERVIN STEIN Primary Examiner means with said drive gear.

3. The improvement defined in claim 1 wherein said DONALD PARKER Exammecylindrical portions of said rollers are formed of nylon. 25 R.FELDBAUM, Assistant Examiner.

1. IN A KNITTING MACHINE HAVING A PLURALITY OF CIRCULARLY ARRANGEDNEEDLES, A PLURALITY OF THREAD SUPPLY ROLLS PROVIDING ELASTIC THREAD FORTHE NEEDLES AND A KNITTING MACHINE DRIVE MECHANISM, THE IMPROVEMENTWHICH COMPRISES APPARATUS FOR FEEDING THE ELASTIC THREAD TO THE NEEDLESUNDER A SELECTIVELY VARIABLE, CONSTANT AND UNIFORM TENSION, SAIDAPPARATUS INCLUDING A MOUNTING MEMBER IN THE FORM OF A FIXED RINGJUXTAPOSED ABOVE THE NEEDLES IN THE KNITTING MACHINE, SAID RINGINCLUDING AN INNER VERTICALLY EXTENDING WALL AND A JUXTAPOSED GENERALLYPARALLEL, OUTER WALL DEFINING A SPACE THEREBETWEEN, A PLURALITY OF PAIRSOF THREAD TENSIONING ROLLERS CARRIED BY SAID MOUNTING MEMBER WITH SAIDROLLERS POSITIONED ON THE OUTSIDE OF SAID OUTER WALL OF SAID RING, EACHOF SAID PAIRS OF THREAD TENSIONING ROLLERS INCLUDING COACTING, SMOOTHSURFACED, ROLLERS HAVING CYLINDRICAL PORTIONS BETWEEN WHICH THE THREADPASSES, EACH OF SAID ROLLERS INCLUDING A STUB SHAFT ROTATABLY SUPPORTEDBY SAID RING, SAID STUB SHAFT OF ONE OF SAID ROLLERS OF EACH OF SAIDPAIRS EXTENDING THROUGH SAID OUTER AND INNER WALLS OF SAID RING ANDCARRYING A ROLLER GEAR ON THE INSIDE OF SAID RING, A COMMON TENSIONINGROLLER DRIVE MEANS OPERATIVELY ASSOCIATED WITH ALL OF SAID ROLLER GEARS,RESILIENT MEANS CARRIED WITHIN SAID SPACE AND OPERATIVELY ENGAGING SAIDSTUB SHAFT OF THE OTHER ROLLER OF EACH OF SAID PAIRS TO URGE SAID OTHERROLLER TOWARD SAID DRIVEN ONE ROLLER OF SAID PAIR TO THEREBY DRIVE SAIDOTHER ROLLER BY FRICTIONAL CONTACT, SAID COMMON TENSIONING ROLLER DRIVEMEANS INCLUDING A RING GEAR SLIDINGLY MOUNTED IN A GROOVE IN SAID INNERWALL OF SAID RING AND ROTATABLE RELATIVE TO SAID RING, A VARIABLE SPEEDCONTROL MEANS OPERATIVELY INTERCONNECTED WITH THE KNITTING MACHINE DRIVEMECHANISM AND BEING OPERABLE INDEPENDENTLY OF THE KNITTING MACHINE DRIVEMECHANISM, SAID RING GEAR BEING PORVIDED WITH TWO SEPARATE SETS OFTEETH, A DRIVE GEAR OPERATIVELY INTERCONNECTED WITH SAID VARIABLE SPEEDCONTROL MEANS AND INTERENGAGING WITH ONE OF SAID SETS OF TEETH OF SAIDRING GEAR, THE OTHER OF SAID SETS OF TEETH OF SAID RING GEARINTERENGAGING WITH ALL OF SAID ROLLER GEARS, OPERATION OF THE KNITTINGMACHINE CAUSING A SYNCHRONIZED AND SIMULTANEOUS DRIVING OF SAID THREADTENSIONING ROLLERS TO FEED THREAD TO THE NEEDLES, AND ADJUSTMENT OF SAIDVARIABLE SPEED CONTROL MEANS EFFECTING A SIMULTANEOUS AND UNIFORMMODIFICATION OF THE TENSION ON THE ELASTIC THREAD BEING FED TO ALL OFTHE NEEDLES OF THE KNITTING MACHINE.